Apparatus for producing an annular corrugated spring

ABSTRACT

An apparatus for continuously producing an annular corrugated spring, said apparatus having forming roller means including a plurality of pairs of forming rollers for applying to an elongated band-like spring blank a predetermined radius of curvature in the plane of the blank to provide a circular form therein, means including a pair of co-operating waved rollers having complementarily waved contours for applying corrugated configuration to the blank passing through the rollers, and means for cutting the corrugated blank at a predetermined position to provide an annular corrugated spring.

United States Patent Mino et al.

[451 Sept. 16, 1975 APPARATUS FOR PRODUCING AN ANNULAR CORRUGATED SPRING Inventors: Hiroshi Mino; Tadashi Sasatani;

Tadaki Kobayashi, all of Hiroshima, Japan Assignee: Toyo Kogyo Co., Ltd., Hiroshima,

Japan Filed: Dec. 5, 1973 Appl. No.: 421,764

Foreign Application Priority Data Dec. 8, 1972 Japan 47-123798 US. Cl. 72/132; 72/185; 72/196 Int. Cl. B21F 11/00 Field of Search 72/129, 130, 132, 146, 72/185, 168, 196; 29/173, 156.6, 156.62, 156.63; 277/160, 161, 162; 267/15, 167

References Cited UNITED STATES PATENTS 7/1940 Yoder 72/132 2,243,351 5/1941 bowry 72/130 2,794,477 6/1957 Sjobohm 72/142 3,284,880 11/1966 Meyer 29/1566 Primary ExaminerC. W. Lanham Assistant ExaminerRobert M. Rogers Attorney, Agent, or FirrnFleit & Jacobson [5 7 ABSTRACT An apparatus for continuously producing an annular corrugated spring, said apparatus having forming roller means including a plurality of pairs of forming rollers for applying to an elongated band-like spring blank a predetermined radius of curvature in the plane of the blank to provide a circular form therein, means including a pair of co-operating waved rollers having complementarily waved contours for applying corrugated configuration to the blank passing through the rollers, and means for cutting the corrugated blank at a predetermined position to provide an annular corrugated spring.

9 Claims, 8 Drawing Figures PATENTEU SEP 1 61975 sum 2 0f 3 FIG.3

FiG.5

APPARATUS FOR PRODUCING AN ANNULAR CORRUGATED SPRING The present invention relates to an apparatus for producing an annular corrugated spring. More particularly, the present invention relates to an apparatus for producing an annular corrugated spring from an elongated flat blank material. g

In a rotary piston type engine having a substantially triangular rotor disposed for rotation in a trochoidal' cavity defined in a casing, annular oil seal rings are disposed between the side surfaces of the rotor and the adjacent inner surfaces of the casing. For this purpose, the rotor is provided in the side surfaces with annular grooves for receiving such oil seals. In order to force the oil seals into sealing contact with the adjacent surfaces of the casing, an annular corrugated spring is disposed behind each of the oil sealrings.

Hithertofore, such an annular corrugated spring has been produced by separate steps of press forming an elongated band-like blank into a plane annular ring and thereafter applying a corrugated form. However, the conventional process is disadvantageous in that it is time-consuming and requires an increased production cost. Further, since the corrugated form is applied through a pressing operation, substantial deformation is produced after heat treatment due to non-uniform distribution of residual stress.

Therefore, the present invention has an object to provide an apparatus which can continuously perform the steps of forming an elongated band-like spring blank into a plane annular shape and then applying a corrugated form to the blank to form an annular corrugated spring.-

Another object of the present invention is to provide an apparatus which can produce an annular corrugated spring having uniform distribution of residual stress.

A further object of the present invention is to provide an apparatus in which an elongated band-like spring blank is applied with a uniform radius of curvature in the plane of the blank.

Still further object of the present invention is to provide novel means for cutting a formed spring blank to provide a substantially annular spring and at the same time forming the cut end of the spring.

According to the present invention, the above objects can be achieved by an apparatus comprising forming roller means including a plurality of pairs of forming rollers for applying to an elongated band-like spring blank a predetermined radius of curvature in the plane of the blank to provide a circular form therein, means including a pair of co-operatingwaved rollers having complementarily waved contours for applying cormgated configuration to the blank passing through the rollers, and means for cutting the corrugated blank at a predetermined position to provide an annular corrugated spring. Preferably, the forming rollers comprise a plurality of outboard rollers having stationary axes and corresponding number of inboard rollers which are resiliently urged to the outboard rollers for cooperation therewith. The cutting means should preferably be mounted in the apparatus so that it is moved along the path of the formed blank at a speed synchronized with the feeding speed of the blank. It is further preferable that the cutting means is also provided with means for shaping the cut end of the blank.

the line III-III in FIG. 1;

FIG.- 4 is a sectional view taken substantially along the line IV-IV in FIG. 2;

FIG. 5 is an enlarged perspective view of waved roller means used in the apparatus shown in FIG. 1;

. FIG. 6 is an enlarged perspective view of cutting means;

FIG. 7 is a perspectiveview of an annular corrugated spring; and

FIG. 8 is an enlarged elevational view of forming rollers.

Referring now to the drawings, there is shown an apparatus for producing an annular corrugated spring C which is, as shown in FIG. 7, circular but waved or corrugated as designated by B in the direction perpendicular to the plane of circle. The apparatus comprises a plane circle forming section 1 for applying a predetermined radius of curvature to an elongated ribbon-like spring blank A in the plane of the ribbon, a wave forming section 2 for applying the waved or corrugated configuration to the blank, and cutting means 3 for cutting the blank to a predetermined length so as to obtain an annular corrugated spring C as shown in FIG. 7.

The plane circle forming section 1 includes a plurality (four in the case of the illustrated embodiment) of outboard forming rollers 4a, 4b, 4c and 4d, and inboard forming rollers 5a and 5b which co-operate with the outboard rollers 4b and 40, respectively. The rollers 4a, 4b and 4c are rotatably supported on the frame of the apparatus and the roller 4d is mounted on an arm 7 which is swingable about the axis of the roller 40. The arm 7 has an upward extension 7a which is provided with an internally threaded hole for engagement with a radius adjusting screw 8. The screw Sis rotatably but axially immovably mounted on the frame of the apparatus. The forming rollers 5a and 5b are supported by a swingable lever 9 which is rotatably mounted at its intermediate portion on an end of a swingable arm 11. The arm 11 is pivotably mounted at its intermediate portion by a shaft 10 on theframe. A spring 12 is disposed to act on the other end of the arm 1 1 so as to bias it in the clockwise direction. An adjusting screw 13 is combined with the spring 12 so as to adjust the bias force of the spring. I

As shownin FIG. 8, the forming roller 4b has circumferential groove 4' for receiving one of side edges of the blank A. The roller 5a co-operating with the roller 4b has a smooth surface which engages with the other side edge of the blank A. It should be noted that the rollers 4a, 40 and 4d have the same configuration as the roller 4b and the roller 5b has the same configuration as the roller 5a, so that they will not be described in detail. The rollers 4a, 4b and 4c are provided with gears G1 1, G and G respectively and the gears G and G are driven by a drive shaft 25 through gears G G G G G and G so as to positively drive the rollers 4b and 4c. The rotation of the gear 6,, is transmitted to the gear G through a gear G so that the roller 4a is also positively driven. The roller 4a serves to guide the blank A between the rollers 4b and 5a, and the blank A is applied with a predetermined radius of curvature in the plane of the blank as it is passed through the path between the rollers 4b, 4c and 5a, 5b. The radius of curvature can be determined by the position of the roller 4d which is adjustable through rotation of the screw 8. When there is any variation in the width of the blank A, the arm 11 is swung about the'shaft to accommodate the possible variable.

The wave forming section 2 comprises a pair of rollers 2a and 2b having complementarily waved contours as shown in FIG. 5. The rollers 2a and 2b are driven in the same direction by the drive shaft 25 through gears G and G which mesh with the gears G and G As the circularly curved blank A is passed through the rollers 2a and 2b, a corrugation or waved form is applied to the blank A.

The cutting means 21 comprises a swingable casing 21 mounted rotatably at one end of a rotatable shaft 20 which is driven through gears G G G and G In the casing 21, there are disposed a pair of end forming dies 15 and 16 which have co-operating spring end forming portions. The dies 15 and 16 are also provided with shearing edges for co-operation with a cutting punch member 18' which is slidable along the end surfaces of the dies. A leaf spring 22 is disposed between the punch member 18 and the die 15 and a weaker spring 22 is disposed between the dies 15 and 16. As shown in FIG. 2, a swingable actuating lever 19 is provided on the casing 21 and acts on the punch member 18 to force it into cutting operation. The casing 21 is connected through a crank mechanism 24 with a drive shaft 26 which is driven by a gear 16 so that the casing 21 is reciprocatingly swung through the angular distance D shown in FIG. 1. The shaft has a cam 23 mounted on one end thereof for co-operation with the lever 19. Thus, in response to the relative movement between the cam 23 and the lever 19, the latter is forced rightwardly as seen in FIG. 2 to actuate the punch member 18. In the initial stage of the movement of the member 18, only the spring 22 is deflected and the dies 15 and 16 are closed to form the blank A as shown by E in FIG. 6. During a further movement of the punch member 18, the spring 22 is deflected so that the member 18 is allowed to move to a position to cut the blank A. It is one of the important features of the invention that the casing 21 carrying the cutting mechanism is moved along the circular path of the blank by the crank mechanism 24 in synchronism with the movement of the blank when the cutting operation is performed, so that the blank can be cut without any local deformation.

From the above descriptions, itwill be clear that the invention provides an apparatus which can continuously produce an annular corrugated spring. Although the invention has thus been shown and described with reference to a preferred embodiment, it should be noted that the invention is in no way limited to the details of the illustrated structures but changes and modifications may be made without departing from the scope of the appended claims. A

We claim:

1. An apparatus for producing an annular corrugated spring from an elongated flat blank, said apparatus comprising forming roller means including a plurality of pairs of forming rollers for applying to an elongated band-like spring blank with flat faces a predetermined radius of curvature to provide a circular formed blank with the faces of the blank normal to the radius of curvature, means including a pair of co-operating waved rollers having complementary waved contours for applying a corrugated configuration to the circular formed blank passing'through the rollers to provide a circular formed corrugated blank with the corrugations being defined inwardly and outwardly of the mean periphery of the blank, and cutting means for cutting the circular formed corrugated blank at a predetermined position to provide an annular corrugated spring.

2. An apparatus in accordance with claim 1 in which said forming roller means include a first set of rollers having stationary axes and a second set of rollers which are resiliently urged to the first set of rollers for cooperation therewith.

3. An apparatus in accordance with claim 2 in which said first set of rollers have circumferential groove for receiving one of side edges of the blank.

4. An apparatus in accordance with claim 2 which further includes a third roller which is adjustable in posaid moving means includes a swingable member which is reciprocatingly swung in synchronism with the movement of the blank.

8. An apparatus in accordance with claim 7 further including means for, actuating the cutting means when it is moved in the direction of movement of the blank.

9. Method for producing an annular corrugated spring from an elongated flat blank comprising the steps of forming an elongated band-like spring blank having flat faces with a predetermined radius of curvature into a circular formed blank with the faces of the blank normal to the radius of curvature, and corrugating the circular formed blank to deform portions thereof inwardly and outwardly of the mean periphery of the blank. 

1. An apparatus for producing an annular corrugated spring from an elongated flat blank, said apparatus comprising forming roller means including a plurality of pairs of forming rollers for applying to an elongated band-like spring blank with flat faces a predetermined radius of curvature to provide a circular formed blank with the faces of tHe blank normal to the radius of curvature, means including a pair of co-operating waved rollers having complementary waved contours for applying a corrugated configuration to the circular formed blank passing through the rollers to provide a circular formed corrugated blank with the corrugations being defined inwardly and outwardly of the mean periphery of the blank, and cutting means for cutting the circular formed corrugated blank at a predetermined position to provide an annular corrugated spring.
 2. An apparatus in accordance with claim 1 in which said forming roller means include a first set of rollers having stationary axes and a second set of rollers which are resiliently urged to the first set of rollers for co-operation therewith.
 3. An apparatus in accordance with claim 2 in which said first set of rollers have circumferential groove for receiving one of side edges of the blank.
 4. An apparatus in accordance with claim 2 which further includes a third roller which is adjustable in position with respect to the first set of rollers to determine the amount of radius of curvature applied to the blank.
 5. An apparatus in accordance with claim 1 which includes moving means for moving the cutting means along the path of the formed blank in synchronism with the movement of the blank during cutting.
 6. An apparatus in accordance with claim 1 in which said cutting means includes die means for shaping the cut end of the blank.
 7. An apparatus in accordance with claim 5 in which said moving means includes a swingable member which is reciprocatingly swung in synchronism with the movement of the blank.
 8. An apparatus in accordance with claim 7 further including means for actuating the cutting means when it is moved in the direction of movement of the blank.
 9. Method for producing an annular corrugated spring from an elongated flat blank comprising the steps of forming an elongated band-like spring blank having flat faces with a predetermined radius of curvature into a circular formed blank with the faces of the blank normal to the radius of curvature, and corrugating the circular formed blank to deform portions thereof inwardly and outwardly of the mean periphery of the blank. 